Eric Hopton for redOrbit.com - Your Universe Online
Images of the Earth at night are an exceptional source of human geographical data, as artificial light illustrates human activity in a way that daytime images could never do.
Some of those images have shown that, when night falls, American cities are many times brighter than their German counterparts, and that those German cities emit several times less light per capita than comparably sized American cities. The findings have been...

Nature Photonics is a peer-reviewed scientific journal established in 2007 and published monthly by the Nature Publishing Group. As with other Nature journals, this periodical has no external Editorial Board with editorial decisions made by a fully-functioning in-house team.
The journal covers research related to optoelectronics, laser science, imaging, communications, and other aspects of photonics. It publishes review articles, research papers, news and commentary, and research...

A magnifying glass is a convex lens, usually mounted in a frame with a handle, which is used to produce a magnified image of an object. The glass works by creating a magnified virtual image of an object behind the lens. However, the distance between the lens and the object must be shorter than the focal length for the glass to work. If the distance is not correct then the image will appear small and inverted.
Many magnifying glasses are mounted on a stand to insure the proper distance...

UV Astronomy -- UV astronomy is the branch of astronomy and astrophysics which deals with objects visible in ultraviolet (UV) radiation.
UV radiation ranges approximatively from 10nm (extreme UV) to 380nm (near UV).
Ultraviolet line spectrum measurements are used to discern the chemical composition, densities, and temperatures of interstellar medium, and the temperature and composition of hot young stars. UV observations can also provide essential information about the evolution of...

Electromagnetic Spectrum -- The electromagnetic spectrum describes the various types of electromagnetic radiation based on their wavelengths.
Radio, representing wavelengths from a few feet to well over a mile, is at one end of the spectrum. Gamma ray radiation is at the other end: the wavelength of the harder types is so short, in the subatomic range, that we do not have instruments capable of directly measuring it.
While the above classification scheme is generally accurate, in...

Electromagnetic Radiation -- Electromagnetic radiation is a combination of oscillating electric and magnetic fields propagating through space and carrying energy from one place to another.
Light is a form of electromagnetic radiation. The theoretical study of electromagnetic radiation is called electrodynamics, a subfield of electromagnetism.
When any wire (or other conducting object such as an antenna) conducts alternating current, electromagnetic radiation is propagated at the same...